About 55,000 Chinese registered marriages to foreigners or Chinese from Hong Kong, Macao and Taiwan with civil affairs departments in 2013, a rise of 12 percent compared with three years ago, according to the Ministry of Civil Affairs.

It did not give details such as the Chinese gender proportion in these marriages, or overseas spouses' ages or place of origin.

About 13.4 million people on the Chinese mainland married last year, the ministry said.

Sun Xiaomei, a professor specializing in marriage and women's studies at China Women's University in Beijing, said the number of Chinese marrying overseas residents could be much larger, as the government does not have figures for Chinese who register their marriages overseas.

Zhou Xiaopeng, a marriage specialist from dating website baihe.com, said there are two main reasons for the rising number of Chinese marrying overseas residents.

"Compared with Chinese men, foreigners care less about appearance and age. Therefore, an increasing number of educated Chinese women tend to date and marry Western men," she said.

On the other hand, China's imbalanced gender ratio has resulted in more single men, especially in remote or less developed areas, looking for spouses overseas, she said.

The latest national census figures show a wide gender gap in China, with 118 male births for every 100 female ones.

In recent years, media reports have exposed more Chinese men from rural areas buying brides from Vietnam or other Southeast Asian countries through illegal agencies, Zhou said.

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